Alarm circuits for space discharge systems



Jan. 7, 1930.

M. E. FULTz ET A1. 1,742,906

ALARM CIRCUITS FOR SPACE DISCHARGE SYSTEMS Filed May 26, 1924 2 Sheets-Sheet l xk) ci@ 2@ Figi. fffv Tonfiwof y M. #j

Jan. 7, 1930. M. E. FUL'rz ET AL ALARM CIRCUITS FOR SPACE DISCHARGE SYSTEMS Filed May 26, 1924 2 Shee\`,s-Sheev EE t 2552K 2 Estas( in PPCGEE-L 2' Patented Jan. 7,v 1930 UNITED STATES PATENT OFFICE MILES E. FULTZ, OF BROOKLYN, AND HARRY R. KNETTLES, OFPORT JEFFERSON, NEVI YORK, ASSIGNORS TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK ALARM CIRCUITS FOR SPACE DISCHARGE SYSTEMS Application filed May 26,

This invention relates to indicating devices for alarm and protective circuits used in connection with high voltage amplifier and other similar systems wherein energy of such value is used that the failure of some part of the system may cause material damage to the amplifying devices or other parts ofthe apparatus.

An object of this invention is to provide for giving an indication whereby the attention of the operator is attracted upon the operation of a part of the control circuit.

A system in which the features of the invention are employed comprises a high power amplifying system in'which the waves to be amplified pass through several stages before reaching the final amplifying set. A high frequency wave 'is modulated in accordance with speech frequency waves. From this modulated wave is selected one side band; this side band is changed in frequency by means of another wave and the resultant waves passed through two stages of low power amplification to an amplifier of intermediate power. From this amplifier, the waves pass to a high power amplifier, i. e., to an amplifier having a high frequency energy output of the order of 200 kilowatt-s, and are impressed upon an antenna from which they "o are radiated.

The invention comprises a plurality of lamps or visual signal devices adapted to indicate operation of any of the various audible alarm and protective apparatus associated with the circuits of an amplifying system.

The protective system comprises a master control circuit having included therein conl tacts made by water-flow control devices, temperature governed relays and a plurality of relays connected to various parts of the amplifying system. Interlocked with the master control circuit is a power control circuit for controlling the power supplied by an alternating current source through a rectifying system.V

Previously, the only indication aorded the operator that some part of the protective system had operated was the sounding of a horn. It was then necessary that he inspect 1924. Serial No, 716,043.

each element of the circuit until the one affected was found. v

To alleviate this time consuming procedure, a lamp or visual signal has been associated with each of several parts of the circuit. Operation of` one of these signal devices immediately indicates to the operator in which part of the circuit the failure has occurred and he may very easily trace the trouble from that point.

rThe novel features of the invention will beV readily apparent by reference to the following ydescription read in conjunction with the attached drawings, wherein the invention is shown as applied toy a protective arrangement associated with a radio transmitting system including space discharge devices as amplifiers, in which Fig. 1 illustrates a schematic circuit of a transmtting system employing high power amplifying space discharge tubes yin c;onnec tion with which the present invention is used.

Fig. 2 shows the arrangement of the plate circuits of the amplifier tubes, each circuit having included therein a relay which operates when the space current supplied to the tube reaches a predetermined value above normal, the operation of which relay opens the master control circuit.

Fig.A 3 is a diagram of the master control circuit having interlocked .therewith the power control circuit and the associated indicating or signal circuit.

In Fig. 1, circuit 10, including microphone 11, represents a source of speech frequency signal waves. Such waves are applied to the grids of the I balanced ymodulator 12 which is supplied by high frequency waves from an oscillator 12. One side frequency or band of the modulated waves is selected by the lter 13 and impressed upon the modulator 14. The side band is changed in frequency by being combined with waves from another high frequency wave generator 14 in the balanced modulator 14. The generator 12 may have a frequency of 33 kilocycles and 14: a frequency of 934k1ocyc1es which produces one side band in the output circuit of modulator 11i having a frequency based on 60 kilocycles. This side band is selected and the modulators 12 and 14 may be of.y a 'type similar to that disclosed in Carson Patent 1,343,307, June 15, 1920. Filters 13 and 15 are of the type described in Campbell Patent 1,227,113, May 22, 1917. lVaves from amplifier 17 are impressed upon amplifying.

system 19 which comprises a plurality of vacuum tubes and has a power output of'intermediate value, for example, 15 kilowatts. Amplifier system 19 feeds into a high power amplifying .system 20,l comprising a plurality of high power, water-cooled space discharge tubes, which in turn supplies signal modulated waves tothe aerial 22 through the tuned circuitf21. The anode circuits of the amplifying systems 19 and 20 are supplied with direct current from the rectifying system 23 which is supplied with three-phase alternating current from the source 24. A

Fig.'2 represents a circuit diagram ofthe amplifier of Fig.V 1. Waves to be amplified'from the source 30 are impressed upon the grids of tubes 31 through the transformer 32, which may have an iron core under certain conditions,-and circuit 33, comprising inductance 34 and resistance 35. Negative potential is impressed upon the grids of tubes 31 from the source `89 (Fig. 3), the positive side of which is grounded. The filaments of tubes 31 are heated by current from source 100 through Vthe transformer 37. The network 38, which is grounded at its midpoint, serves as a return path to ground for the current supplied to the plates. eluded therein a resistance 39 which controls the value of the current supplied, to the filament. Theplates are supplied with current through a common bus bar 45 connected to the output side of a` rectifier 23 which in turn is supplied with alternating current by a source 24. Rectified current from the bus bar `45 passesl through relay 7 and the circuit comprising resistance 41 and inductance VV42 to the plate of each of the tubes. Resistance 41 and inductance 42 together offer high impedance to the flow of undesired high frequency currents while inductance 42 provides a low impedance pathfor the waves to be amplified. The combination ofthe two in each platecircuit tends to reduce singing.

Theirvefect is to'increase the damping. to a point at which oscillations will -not be supported. A capacity 43 which provides a low impedance path for Waves of high frequency .and a high impedance to rectified current is shunted across the relay 7, thereby causing Y cillations.

tact at 40, the relation of which to the master control circuit is shown in Fig. 3.

'damage lto the tubes.

Each filament circuit has inthe rectified current' to flow through the relays to the plates. Interconnecting the plates of the amplifier tubes is a path including resistances 44 which serve to assist in suppressing undesired high frequency os- These resistances make it possible for the same potentialto be impressed upon the plates of each discharge device. The relays 7 do vnot pick up their armatures 52 on normal space current but are so adjusted as to pick up only on current'of some predetermined value above normal. When armature 52 is operated, a spring or gravity operated .element 53 qmoves against a small projecting lever 54 secured on shaft 55. Inspection of the elements 53 indicates which tubehas failed. The element'53 when released rotates the shaft 55 sufiiciently to causer a projecting arm, 56 to break the con- Horn'gap 123 connected to grid bus bar5. whichA extends from the output circuit of amplifier 1 9 to the grids of amplifier 20 flashes over on voltages that might cause an arc withinv the tubes of amplifier 20. On flash over the relay 125 is energized, picking up its armature 127 and allowing spring or gravity operated Iarm 126 to drop. The knob on the arm 126, upon dropping breaks the contact 128 and closes contact 129. The breaking of contact 128 inserts a resistance 114 in. series with the field 140 (Fig. 3) of the generator 89, thereby reducing the gener.- ator voltage to a very low value preventing The closing Vofy contact 129 closes a circuit which causes lamp 106 to be lighted and horn 104 to sound. The reduced voltage is not sufficient to keep relay 86 (Fig. 3) energized, consequently it opens and power is cut off from the tubes in al manner to be explained later. Y

Fig. 3 is a schematic representation of the `alarm circuit embodying this invention and used in connection with fthe system shown in Fig. 1. Three-phase current to bek rectified is fed to the partially illustrated.rectifyingl system 23 from the source 24. Oilswitch 60 in the circuit controls thev connection of the power source to the rectifier. In two of the leads of the three-phase source are connected current transformers 6 1 and- 62which are adapted to operate relays 63 andk 64 respectively. The armatures of'these relaysare so arranged that the energization of either relay will close a circuit through a third relay 65. Current for' relay 65 is supplied by the source Aof direct current 66. Actuation ofrelay 65 breaks a circuit throughthe bank of lamps 67 and `holding Scoil 68 of Vthe oil switch 60. The oil switch 60 is closedbymean's of threeposition'switch 69. Lamps 8 and 9 indicate whether switch 69 is open or closed. Rectifier system 23 is equipped with a plurality of horn gap arresters 70, to prevent excess soV voltages on the line being supplied to the rectiliers. Resistance 71 is located in each horn gap circuit to determine the value of the current which is supplied to relay 72 when any gap sparks over. By-pass condenser 7 3 is shunted across the grounded relay 72. Relay 72 when energized, which happens when any one of the gaps sparks over, picks up its armature and breaks contact 7e included in the master control circuit. The plate circuit o each space discharge tube in the rectifying system 23 is supplied with a relay circuitbreaker 84, some of which are shown, to prevent the supply of excessive current to the plates of the tubes. Rectilied current from the rectiiier system passes through the iron core choke coil 7 5 and inductance 7 6 which tend to prevent singing in the circuits of the amplifiers 19 and 20. A lead connects point 7 8 to the bus bar 77 carrying the rectified current. Switch arm 116 is constructed of metallic conductive material with a conductive band 117, insulated from the arm. When contact 117 in the power control circuit is open switch 116 engages and grounds the direct current bus bar 77 at the point 7 8. Bus bar 77 is provided with a horn gap 79 and grounded relay 80 which picks up its armature and breaks theV master control circuit when abnormal voltage on the bus 77 causes the gap 79 to spark over. Resistance 81 in the relay circuit limits the current which flows to the relay 80. The plates of the two tubes of the amplifier 19 are connected to relays 82 and 83 individually and the contacts made by these relays in the master control circuit are connected in series. These relays are so wound that they do not pick up their armatures when normal current flows through the plate circuits but do so on overload, thereby opening contacts in the master control circuit. Relay operated circuit breakers for the amplifier 20 have been described with reference to Fig. 2 and their position in the master control circuit is shown by arms 56 and contacts 40. The position of relay 125 and its associated apparatus, the operation of which has been explained in connection with Fig. 2, is shown with reference to the alarm circuit, the grid-bus bar 5 and the grid polarizing generator 89. Relay 85 is a quick-acting release relay. It must be restored to position in which its armature makes contact with the power control circuit manually, being held in that position by normal voltage in the master control circuit. Relay V86is a remote controlled contacter which picks up its armature and closes the power control circuit when current above normal liows through the master control circuit, but is held in that position by normal current. lVhere no current passes through the master control circuit, the contact made by armature of relay 85 opens at high speed. l/lfhen current below normal value liows through the master control system, which happens when relay 125 operates relay 86 opens. The contacts of the relays 85 and 86 are in series in the power control circuit. Negative potential for the grids of the tubes of the amplifiers 19 and 20 is supplied by the motor generator set 89 through a lead 120 which extends from the negative terminal of the source 89 (Fig. 3) to the potentiometer 131 (Fig. 2) and grid circuit filter 132, through the input resistance 35of the grids of tubes 31. The positive side oi the generator is grounded through one terminal of the switch 91. Condensers 90 are shunted across the grid polarizing generator 89 to shunt off to ground any high frequency voltages picked up by the generator connections. The field of' generator 89 is represented by coil 140. The amplifier 19 is supplied with grid potential from the source 89 by circuit connections (not shown) similar to those connected to the input circuit of the amplifier 20.

Resistances 92 and 93 are placed in the alarm circuit to regulate flow of current through the circuit. Resistance 93 can be shunted out of the circuit by master control push button 941-, thereby allowing current above normal to pass through the circuit to cause relay 86 to pick up. Contact devices 96, 97, 98 and 99 are controlled by water flow devices such as that shown at 95. When water flows at the desired rate in a tube cooling system, water iow device 95 causes contact device 96 to rotate in a counter-clockwise direction to break the vupper contacts and close the lower. Vhen the rate of flow ot' water through the cooling system falls below a safe value the control device rotates in a clockwise direction closing the uppercontacts and b-reaking the lower. Device 96 is actuated by the water iowing through the tubes of amplifier 19, devices 97 and 98 by the water flow through the two sets of tubes which make up amplifier 20 and the device 99 by the water flow through the tubes of the rectit'ying system 23. Current tor heating the filaments of the amplifier tubes is supplied by a source of altrnating current 100 through the switch 101 and the four pole switch 102. A transformer 103 is connected across one phase of the alternating current circuit to supply current for the lights 106,

107 and 108 and to the transformer 105V which supplies energizing current to thesound signal device 104. For operating in'noisy surroundings the horn 104 may be a loud sounding device such as an automobile horn. A variable resistance is connected in each light circuit to limit the iiow of current through the lamp. The lamps are connectei in parallel with each other, having the primary of transformer 105 in series with the line so that upon closure of any one or more of the lamp circuits the horn will operate. A circuit from the source of alternating current 100 goes to the motor generator set 109.

, The output of the generator passes through four-pole switch 110 to the rectiiers and is there used to heat the filaments of the rectifier tubes. The fourth poles of each of the switches 102 and 110 are connected in parallel with each other and in series with the secondary of transformer 103 so that the closing of either switch will cause the lamp lighting circuit to be in operative condition. By

ythis switching arrangement it is possible to and close a circuit which causes lamp 106 to be lighted and the horn 104 to sound. The rclockwise rotation of any one of the contact devices 96, 97, 98 and 99 will close a circuit through the upper contact of that device and cause a lamp 107 to be lighted and the horn to sound. At different points in the cooling system thermometers 115 are located. l/Vhen the ltemperature of the cooling water reaches a predetermined danger point a circuit is closed from ground through the thermometer affected, through the secondary of transformer 119 and through the relay 1118 to ground. The primary of transformer 119 is supplied with alternating current from the three phase source 100. When the left hand armature of. relay 118 is picked up, a circuit is closed which lights a lamp 108 and causes the horn 104 to be sounded. When the right hand armature of the relay 118 is picked up the master control circuit is opened.

Y Operation To putV `the radio telephone transmitting set in operating condition a definite -procedure must be followed. The system is illustrated in Fig. 3 as being in normal operating condition with the various contacts either opened or closed as they normally are. The water flow to cool the plates of the amplifier. and rectifier tubes is turned on, causing the control devices 96, 97, 98 and 99 to be rotated in a counter-clockwise direction, opening the upper contacts and closing the lower. Current to heat the filaments of the amplifier and rectifierl tubes is thenturned on by closing switches 101, 102 and 110. Simultaneously, the alarm circuit, including the horn 104 and the lamps 106, 107 and 108, is supplied with current by means of transformer 103. Allthe circuit breakers in the control circuit must be closed. After any break in the master control circuit these contacts 4must be restored tov putthe circuit inV operating condition. During normal oper- 8.4, 72,80, 82, 83 and 85 are closed. Relay 86 is a remote control relay and in connection with relay .85 forms the interlocking means between the master control circuit and the power control system. Contacts are closed. The ground connection is then removed from direct current bus 77 at the point 78 by means of the switch 116. At the same time the power control circuit is closed by means of contact 117.

When the alarm circuit has been put in operative condition, motor generator 89 is started and switch 91 closed. The motor generator 89 supplies negative potential to the grids of the amplifier tubes and also supplies current to the master control circuit. The path of current through this circuit may be traced as follows: from switch 91 through the resistances 92 and 93, lower contacts of control Vdevices 96, 97, 98 and 99, contacts made by one of armatures of relay 118, contacts made by the armatures of relays 84 and 72, contacts 40, contacts made by the armatures of relays 80, 82 and 83 and through relays 85 and 86 to ground. To put the power cont-rol circuit in operative conditionv relay 86 mustv pick up its armature and, since the passage of more than normal current throughv the alarm circuit is required to actuate the relay, resistance 93 is shunted from the line by the master control push button 94, long enough to cause the relay to pick up its armature. Y

Should there be no water flow through any set of tubes, lower contacts of the control devicefor that set wouldbe opened, upper contacts would be closed, lamp 107 lighted and .Y

horn 104 sounded. The lamp would indicate to the operator the nature of the trouble and the section ofthe circuit that had operated.k

Should the water be flowing properly and the temperature normal but one ofthe relay operated contacts be operated to open the circuit, the current in the master control circuit would pass through the lower contacts of the control devices 96, 97, 98 and 99,

tures of relay 118, and through relay 111 to ground. 'Y The armature of relay 111`will close a circuit from ground through resistance 112 through the relay 113 and negative side of generator 89. The relay 113 in picking up its armature closes a circuit which llights lamp 106 and causes horn 104'to be sounded thereby through contactmade by one of the arma- Y tion, power may be supplied to the rectifiers from source 24. Switch 69 is actuated to engage the middle contact, allowing current to iiow from one side of the source of direct current 66 through the contacts made by the armature of relay 65, through the make-beforebreak switch 69, bank of lamps 67, holding coil 68, contact band 117, contacts made by armatures of relays 86 and 85 to the opposite side of the source of direct current 66. The switch 69 is then thrown to the right, shorting out the lamps 67 and allowing full current to pass through the holding coil 68 which picks up its armature thereby closing the oil switch 60. After the oil switch 60 is closed switch 69 is thrown hack to the middle position by springs 69', placing the lamps in series with the holding coil. Once closed, the coil 68 will hold the switch 60 closed so long as normal current flows through the power control circuit. Lamps 8 and 9 indicate whether switch 69 is open or closed.

While the set is working a number of causes will throw olf the power. Should excessive current be traversing the rectifier from source 24 either of the current transformers 61 or 62 will energize a relay associated with it, that relay in turn causing contacts to be made whereby relay 65 is energized and the circuit to the holding coil 68 opened. Coil 68, on being deenergized, allows its armature to drop, opening oil switch 60 and shutting off the power to the rectifiers. This trouble would be indicated by the lamp 9 being lighted.

Should the plate of any one of the rectifier tubes receive excessive current, corresponding relay 84 would be energized, breaking the master control circuit at that point. Quick release relay 85 and slow release relay 86 would be deenergized, breaking the power control circuit which causes the relay 68 to be deenergized and the oil switch 60 to open.

t the same time lamp 106 would be lighted and the horn sounded in the manner explained before. By noting which relay had operated the trouble could be quickly attended to.

Should any part of the rectifying system receive excessive voltage the corresponding horn gap would spark over, energizing relay 72, breaking the master control circuit at contact 74 and affecting the two associated circuits in the manner explained in connection with relays 84.

Excessive current to the plates of any of the tubes of amplifier 20 will cause the associated relay 7 to be energized, breaking the corresponding contact 40 and affecting the two interlocked circuits in the same manner.

Excessive plate current in any one of the tubes of amplifier 19 would cause relay 82 or 83 to be energized breaking the master control circuit and shutting down the system.

The horn gap 79 is so constructed that it will spark over at surges of abnormal voltage on the direct currentbus 77, causing relay 80 to be energized, breaking the master control circuit and shutting off power to the rectifier. The power is shut off when the grid voltage supply 89 fails because the con'- trol circuitthen becomes deenergized.

By the arrangement of relays and'86V the master control circuit is interlocked with the power control circuit. Thus any abnormal condition in the amplifying system or in the rectifying system which opens the master control circuit will take the power oli the rectifying system.`

AShould the temperature of the water used to cool the tubes reach too high a point, the thermometer 115 would close a circuit from ground through the thermometer 115, through the secondary of transformer 119 and the relay 118 to ground. Relay 118, by picking up its left hand armature closes a circuit, thereby attracting the operators attention by causing the horn'104 to sound and lighting the lamp 108, and by picking up the right hand armature the master'control circuit is opened.

Push buttons 25 are provided at convenient points about the set. When operated, any of them will ground the master control circuit causing relays 85 and 86 to operate which in turn opens the oil switch 60 without sounding the horn 104.

The rectifier 23 may be run independently of the amplifying system for test purposes by closing the switches 101 and 110 but leaving switch 102 open. The master control circuit would then be in operative condition as described above.

It can readily be seen that the horn 104 is not necessary for the successful operation of the system for it merely indicates that some contact in the circuit has opened, while the lights serve a double purpose, that of attracting the attention of the operator upon the opening of a contact and also of definitely indicating in what section of the circuit the opened contact is located.V

Any one ofthe protective vdevices included in the alarm circuit may be used exclusive of any others and the circuit will function properly when comprising only a part of the devices herein described. Furthermore, other ,protectiveV devices may be added to those shown. It can be seen that the relay 118 may be provided with only one armature, which will cause the lamp to be lighted and that the thermometer can be so adjusted as to make contact at a temperature not dangerous. The operator could then control'the water supply manually to lower the temperature without shutting down the set. It is also evident that there could be an indicating lamp for each contact in the protective circuits, thereby indicating instantly the operation of any one of the contacts.

The present invention is not limited to the y arrangement illustrated, but may bev embodied Y in other constructions withinthe scope of i the following claims. What is claimed is:

1. Ina high power, fluid-cooled space Vdischarge system. having a control circuit therefor comprising a plurality of sections each associated with a control device responsive to a different undesired condition in the system, and means individual to each section for indicating the operationof'the associated control device. Y

2. In a high power Huid-cooled amplifying system having a control circuit therefor comprising a plurality of contacts associated with various parts of saidv amplifying system', said control circuit being divided intoa plurality of sections each including control means for said contacts, said control means being responsive to different undesired conditions in the system, and means individual to each of said sections for indicating the operation of a contact included in said section.

3. A space discharge systemcomprising a plurality of discharge devices, a circuit including a plurality of control means for said devices, said control means being responsive to different undesired'operating conditions of said devices, and means individual to said control means for indicating the operation thereof.r l

4. A space discharge system comprising a plurality of discharge devicesfa circuit including a plurality of control means each responsive to different "undesired conditions in the system, and indicators adapted to be actuated by operation of the respective control means. Y .Y

5. Ina system including a plurality of electric discharge devices, signal means for indicating trouble in the system, a plurality of means respectivelyv responsive to various abnormal operating conditions of thedischarge vdevices for operating said signal means, and a plurality of additional 'signal means -individually responsive to the respective .abnormal conditions tok indicate the general nature of the trouble.

6. In a space discharge system,.a fluidcooling arrangement for a space discharge device, a signal actuated by insulicient fluid supply, a second signal to indicate improper temperature conditions in the fluid supply of the cooling arrangement, a third signal, and means actuated by improper current' conditions in a discharge device of the `system `to actuate the third signal.

In witness whereof, we hereunto subscribe 0111 names.

MILES E. FULTZ. HARRY R. KNETTLRs. 

